Answer:
7
Step-by-step explanation:
We want to find the number 4-digit of positive integers n such that removing the thousands digit divides the number by 9.
__
Let the thousands digit be 'd'. Then we want to find the integer solutions to ...
n -1000d = n/9
n -n/9 = 1000d . . . . . . add 1000d -n/9
8n = 9000d . . . . . . . . multiply by 9
n = 1125d . . . . . . . . . divide by 8
The values of d that will give a suitable 4-digit value of n are 1 through 7.
When d=8, n is 9000. Removing the 9 gives 0, not 1000.
When d=9, n is 10125, not a 4-digit number.
There are 7 4-digit numbers such that removing the thousands digit gives 1/9 of the number.
140.4 m squared because 7.2 times 19.5 is 140.4 m SQUARED
Answer:
x = ±√11 +2
Step-by-step explanation:
Given in the question an equation,
x²- 4x - 7 = 0
Step 1
take 7 to the right side of equation
x²- 4x = 7
Step 2
To create a trinomial square on the left side of the equation, find a value that is equal to the square of half of b, the coefficient of x
2ab = -4x
2xb = -4x
b = -2
Step 3
Take square of b and add it to each side of the equation.
x²- 4x + (-2)²= 7 + (-2)²
x²- 4x + 4 = 7 + 4
x²- 4x + 4 = 11
Step 4
Factor the perfect trinomial square
(x−2)² = 11
Step 5
take square root on both sides
√(x−2)² = √11
(x-2) = ±√11
x = ±√11 +2
Answer:
{-8, -4, 0, 4, 8}
Step-by-step explanation:
brainliest please
